Hi blackmail
Thank you for your reply.
However, when I try to calculate the aspect ratio using the numbers here: http://www.b737.org.uk/techspecsdetailed.htm I don't get the "correct" result (the number on the page).
With your data I'm getting an AR of 9.12 with winglets. Without winglets the number is supposed to be 9.16 according to b737.org.uk. When I calculate the AS without winglet using numbers from that website, I get 8.47 - quite a lot less than 9.16.
Any ideas what I'm doing wrong here?
Last edited by PWMdk; 16th Nov 2015 at 18:12.